The objective of the present study was to evaluate the effects of a selective beta(3)-adrenoceptor agonist, (R, R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1, 3-benzodioxole-2,2-dicarboxylate (
CL 316243), on the acutely obstructed ureter in anesthetized dogs. After a complete
ureteral obstruction produced by the inflation of a balloon
catheter placed within the left lower ureter, the intraluminal ureteral pressure gradually rose to reach a plateau of approximately 52.5 mm Hg.
Intravenous administration of
isoproterenol (a nonselective beta-
adrenoceptor agonist; 10 microg/kg) and
CL 316243 (1 microg/kg) significantly decreased this elevated ureteral pressure (by 74.1 and 77.2%, respectively), with the reduction more sustained with
CL 316243 than with
isoproterenol. In addition, under both
isoproterenol and
CL 316243, urine flow (which had been interrupted by the balloon) was resumed, resulting in further sustained decreases in ureteral pressure. The mean blood pressure decreased and heart rate increased after the administration of both drugs, but these changes were greater in the
isoproterenol group than in the
CL 316243 group. In contrast, i.v. administration of
butylscopolamine (an
anticholinergic agent; 1000 microg/kg) had no evident effects on ureteral pressure or on urine flow. The increase in left kidney weight seen after
ureteral obstruction was suppressed by
CL 316243. We conclude that the selective beta(3)-adrenoceptor agonist tested appears to be more useful than
isoproterenol for reducing ureteral pressure above the obstructed site and for promoting ureteral relaxation and increasing urine flow around the point of obstruction in dogs.